Paper-coating mechanism and process of coating paper



Aug. 26, 1930. 1 A. PARKER 1,774,398

PAPER COATING MECHANISM AND PROCESS OF COATING PPER Filed Jan. 2, 1926 2Sheets-Sheet 1 Q WB Q LO H /N VENTOR A TTORNE V5 Aug. 26, 1930. A.PARKER 1,774,398

PAPER COATING MECHANISM AND PROCESS OF COATING PAPER Filed Jan. 2, 19262 sheets-sheet 2 A TTORNE Y;

Patented Aug. 26, 1930 UNITED STATE-s PA'Il-:NT oFFlcE LUTHEBLA. PARKER,F KALAMAZOO, MICHIGAN, ASSIGNOB T0 THE CHAMPION COATED PAPER. COMPANY,0F HAMILTON, OHIO, A CORPORATION PArEn-coArING-Mcnmsn Annrnocnss orcoa'rma Puna Appueatioalcaieii'. 2,y 192e. serial No. 78,868.

This invention relates to an improved paper coating mechanism andprocess of coating paper.

The objects of the invention are:

First, to provide a simple and durable machine of large capacity, highspeed, and eiiciency. 1

Second, to provide a simple means for securing an even distribution,even appearance 1o and effective surface finish on a coated sheet.`

Third, to provide a machine which is economical as to the coatingmaterial, using no excess and conserving all the surplus.

Fourth, to provide an improved process of handling the sheets withoutundue tension and delivering the same effectively coated to the ioaterfor drying.

Fifth, to' provide an improved continuous process of handling andcoating a web of pa er.

bjects pertaining to details and economies of construction and operationof my invention will definitely appear from the detailed description tofollow.

The invention is clearly defined and pointed outin the claims. Astructure which is/a preferred embodiment of my invention is clearlyillustrated in the accompanying drawing, forming a part 3o if thisapplication, in which:

Fig. 1 is a side elevation view of the machine, portions of the dryingbox being broken away and shown in section.

Fig. 2 is a similar diagrammatic side elevation view, being in brokensection.

Fig. 3 is an enlarged detail transverse sectional view on line 3-3 ofFig. 1.

Fig. 4 is an enlarged detail View from the left hand of Fig. 3 showingdetails of construction of the finishing rolls and their driving andadjustingmeans.

Fig. 5 is a similar enlarged end view of the moistener structure madeuse of when one side only of the sheet is being coated.

Fig. 6 is a side elevation of one of the nozzles. A

The parts are identified by the samenumerals of reference throughout theseveral views.

1 is the roll stand from which the paper lWeb 17 to be coated isdelivered to the canvas looper 2. 3 is the base of the main part of themachine carrying the feed roll structure 4 of a usual construction atits front end.

5 and 6 are the main uprights for carrying 55 the coating roll. Therdriven roll 7 is in an adjustable bearing box 8 between these uprightsand the follower roll 9 is carried in the adjustable bearingbox 10, thepressure on Whichis controlled by usual screw means Vcontrolled by thehandwheel 101. y

,l1 is the cross trough for the coating material. 12 is a centrifugalelectrically driven circulation pump taking the coating mixture throughpipe 13 from the bottom of the 65 trough 11 and delivering the samethrough pipe 14 to header nozzles 15 and 16 for coating one or bothsides of the sheet or web 17.

18 and 19 are the longitudinal top and bottom beams for the main framework of the machine carried by the uprights 5 and 6 and the end posts 20and supporting posts 21 beneath the same at intervals as required. Thesebeams are connected by upright co1- umns 22, 22 which are provided withvertical 75 adjusting ways 23, 24. On these ways are brackets 25 whichcarry the finishing rolls 26 which are supported in boxes '27 that areadjustable up and down by the screw-threaded lugs 28 receiving theupright supporting So screws 29 which are provided with collars 30, 31and are actuated simultaneously by the shaft 32 having worms 33, 33 ateach end meshing with -worm gears 34 on the lower ends of the saidadjustingscrews 29.

The rolls are driven by electric motor 35 provided with sprocket drivingpinions 36 which drive sprocket gears 37 on the ends of the rolls bymeans of sprocket chains 38. These rolls are supported on the guidewayson the opposite sides ofthe uprights 22. The rolls at the left hand sideof the upright are shown with the web 17 passing above the roll andthose on the right of the standard 22, as seen in Fig. 1, are disposedwith the inishing rolls above the sheet. The adjustments enable theproper contact arrangement of the roll to the web 17.

The nishing rolls are driven to rotate against the direction of thetravel of the web 10 17 when both sides are coated. When only the upperside is coated the rolls on the under side are driven in the samedirection as the sheet and serve to support and advance the same withoutundue friction. The rolls 26 are made of highly polished non-corrosivematerial of any kind. This material is preferably of polished steel.

The sheet travels from the finishing rolls to the drier box 46 which hasan eduction iue 47 for carrying away the moisture laden air. Air issupplied to the drier box through the header 48 having upwardlyprojecting connections 49 each terminating in broad fanshaped nozzles 50transverse tothe web and delivering in close proximity to the lunderside thereof, as clearly appears in F ig. 2.

By thus supporting the sheet on the air it is not necessary to providestrong tension and the I same is very readily n delivered through alongdry-box to a tensioning apron 51 seen in Fig. 2. The tensioning aprontensions the sheet through the entire a paratus so that the finishingrolls, acting a ternately on opposite sides in spaced relation to eachother, act against the tension means 51 and can, therefore, be run at acomparatively high rate of speed and finish the surface by a lightfriction contact therewith. The speed giving best results is 21/2 to 3times the speed of the web. The contact is as light and more perfectthan can be secured with a brush.

In normal brushing practice the brushes vibrate laterally of the movingweb, thus displacing the coating fluid and causing it to be distributedevenly, with slight irregularities therein equalized. The result ofapplying the reversely turning rolls in my machine, is that the rollspick up the coating from the sheet and redeposit it again thereon. Topick up very thin films of coating, which seems to be necessary toattain the desired effect, the peripheral speed of the rolls must be.faster than the paper moving thereunder. If the rolls have a peripheralspeed less than that of the paper, the result will be to form transverseridges thereon.

On the end support 20 I mount a pair of reciprocating cross brushes (ofusual coating brush construction) 39 beneath the web and 40 above. Theseeliminate any slight surplus coating and smooth off any irregularitiesand pass the sheet perfectly clean onto the driver 46.

When the coating is done on both sides no moisture is supplied to theweb.

When there is but a single coating on the upper side of the sheet it isnecessary to moisten the lower side to insure even dr ing andconsequently a perfectly flat sheet. his I accomplish by providing aunit similar to the other unit with moistening roll 43 in place of afinishing roll. There is a shelf 41 carrying a cross trough 42 for waterinto which the moistening roll 43 projects. AA wooden doctor 44adjustable by the usual hand screw 45 regulates the amount of moistureon this roll which is delivered to the under side of the sheet byrolling into contact therewith, the roll running in the direction of theweb travel; When the sheet is to be coated on one side only I prefer tolead it first around a roll 53 wherebyit is brought into a position toreceive coating material from nozzle 15, and is caused to follow thesurface of roll 7, which it next contacts for some little distance. Thisis shown in Figures 1 and 2.

In Fig. 1, I show both sprays 15 and 16'and the coating material inprocess of application to both sides of the web. The spray 16 isdelivered on to the top of the web 17 and the lower spray delivers tothe surface of the roll 7 and is passed into contact with the under sideof the web by the roll.

In Fig. 2 I show the method of passing the web through the machine whenone side, the top side only, is coated. Here the lower spray head 15 isdelivering to the top side of the sheet which is being delivered incontact with the lower roll 7. I also here show the moistener roll inoperation moistening the under side of the web 17 as it passes to thedrier so that it will dry evenly. Of course, wherehoth sides are coatedthey are equally moist and the drying will'be done'evenly without injuryto the sheet. I have shown my improved-coating and finishing machine inits preferred form.

Theprocess, it will be noted, consists in the coating of the sheet,tensioning the same and brushing it with a smoothing roller against thetension of the sheet as distinguished from calender rolls operating oneagainst the other, or from bristle or fiber brushes. The tensioning ofthe web makes it possible to do this work' gently and yet at a highspeed securing an effective distribution and finish of the coatingmaterial Withf out any brush marks and Without any Waste, putting on aslight or as heavy a. coat as is required for the particular purpose inhand. It is vpossible by this means to load a sheet with a heavy load ofcoating material where it is desired, or to coat the same with a minimumamount when for any reason that is the requirement. The coating may befor sizing, finish, or any other purpose such as gummed paper.

It is also possible with a single machine to coat either both sides orone side of the sheet by simply cutting off the spray and delivering theweb as required for the purpose, and the machine is of great advantageon that account.

While I have shown a pair of cross reciprocating brushes for acting onthe sheet after it has been finished by the rolls, I desire to statethat a larger number of brushes might be provided at that point, andthat a very good product is secured if no brushes are ikv-sees made useof at all. Whether the surface shall be brushed, or to what extent,after this treatment, is a matter of choice, depending on circumstances.The surface is considerably improved by the brushing and, of course, atthat stage, cannot leave any brush marks on the finished sheet.

Having thus described my invention what I claim as new and desire tosecure by Letters Patent is:

`1. In a machine for coating paper, the combination with means for aplymg a spravable coating substance to t e paper and for limiting thethickness of coating, means for feeding the paper, and separate meansfor spreading said coating comprlsmg a roll impinging upon lthe paper,and rotatedoppositely to the movement of the paper, said roll driven ata peripheral speed greater than the speed of the paper.

2. In a machine for coating paper, the

I combination with means for applying a sprayable coating substance tothe paper and for limiting the thickness of `coating, means for feedingthe paper, and separate means for spreading said coating comprising aroll impingin upon the paper, and rotate oppositely to t e movement ofthe paper, said roll being driven ata peripheral speed greater than thespeed of the paper, and between 2% to 3 times the speed of the paper.

8. In a machine for coating paper, the combination with means for aplying a sprayable coating substance to t e paper and for limiting thethickness of the coating, means for feeding the paper, and separatemeans for spreading said coating comprising a series of rolls impingingupon the paper, and rotated oppositely to the movement of the paper,said rolls being driven at a peripheral speed greater than the speed ofthe paper.

4. In a machine for coating paper, the com bination with meansforspraying a coating travelin web of paper in a controlled thickness, anwithout roviding for an intervenmg drying stage or plasticizing thecoating by a subsequent step spreading said coating.

hand. v

LUTHER A. PARKER.

substance onto the paper, and for limiting the thickness of the coating,means Afor feeding the paper, and separate means for spreading saidcoating comprising a series ofrolls impinging upon the paper, androtated oppositely to the movement of the paper, said rolls being drivenat a ripheral speed greater than the speed of tlia aper, and between 21Ato 3 times the speed o the paper.

e. A process of coating paper which comprises applying a sprays, lecoatin toa traveling web of paper in a controlle thickness, and withoutproviding for an intervening drying stage for plasticizing the coatingby a subsequent step, spreading said coating by picking up coating andredepositing it upon the traveling web by one or more cylindricalsurfaces rotating oppositely to the travel of the paper and at aperipheral speed greater than that of the paper.

6. A process of coating apar which comprises applying a sprayablecoating to a

